Ic Information - Pioneer SX-305RDS Service Manual

SX-305RDS, SX-205RDS
5. IC INFORMATION
¢ The information shown in the list is basic information and may not correspond exactly to that shown in the schematic diagrams.
i SAA6579 (FRONT ASSY: IC801)
Radio data system demodulator (RDS), CMOS IC
The SAA6579 is a demodulator circuit for RDS applications. It contains a 57 kHz
bandpass filter and a digital demodulator to regenerate the RDS data stream out of
the multiplex signal (MPX).
@ Block Diagram
ANTI- 57 kHz
BANDPASS
(8th ORDER)
MUX ALIASING
oO FILTER
SCOUT
COSTAS LOOP
VARIABLE AND
FIXED DIVIDER
CLOCKED
COMPARATOR
CIN (7)
VODA
CLOCK
REGENERATION
AND SYNC
Veet REFERENCE
fa VOLTAGE
(§)
VSSA
RECONSTRUCTION
FILTER
osci Osco Vppb
QUALITY BIT
GENERATOR
(1) QUAL
DIVIDER
BIPHASE
SYMBOL
DECODER
DIFFERENTIAL
T**1 DECODER is REDE
RDCL
TEST LOGIC AND OUTPUT
SELECTOR SWITCH
(15) 157
Via the pin MODE two different crystal frequencies can be used
4.332 MHz
8.664 MHz
LOW
HIGH
@ Pin Function
| 4 | QUAL | O | Quality indication output
PinNo[PinName | vo | _PinFunction
@ Pin Arrangement (Top View)
QUAL RDCL
| 2 | RODA | © | RDS data output
[ 3 [vel | - | Reference voitage output (0.5 VoDA) RDDA T57
} 4 | MUX Zim Multiplex signal input — ésto
Ea VODA | - | +5 V supply voltage for analog part
f 6 | vssa | - | Ground for analog part (0 V) MUX ] Osc!
CIN za Subcarrier input to comparator SAA6579
Vi
| 8 | SCOUT | oO | Subcarrier output of reconstruction filter ey wone
| 9 | move | - | Oscillator mode/test control input VSSA VsspD
| 10 | TEST ad Test enable input in
= TEST
| 41 | Vssp | - | Ground for digital part (0 V)
| 12 | vooo | - | +5 V supply voltage for digital part SCOUT MODE
OSCI za Oscillator input
Oscillator output
57 kHz clock signal output
| © | RDS clock output